How Metals and Amino Acids Effect Guaiacol Peroxidase Activity from Dill

Environmental pollution has been a serious problem since the start of the industrial revolution. The pollution usually comes from industrial wastes, waste water, heavy metal, etc. Heavy metals such as lead, mercury, tin are considered to be toxic to living organisms and enzyme activities. However, metal ions can play essential role in plants and animals as they are involved in fundamental processes such as photosynthesis, respiration and DNA synthesis. Plants with their antioxidant enzymes which are in plant defense system show some stress when they are exposed the metals. One of the iron-heme dependent antioxidant enzymes is peroxidase (POD) enzyme that catalyzes hydrogen peroxide mediated oxidation of different substrates such as phenols. In the present work, Guaiacol peroxidase (POD) was first characterized from the dill (Anethum Graveolens L.) with the optimum pH and temperature. Then, the effects of various metals and amino acids on the dill Guaiacol peroxidase (POD) activity were investigated. The POD activity was tested against eight different metals (Hg(II), Co (II), Cur(II), Fe(III), Mn(II), Pb(II), Zn(II) and Sn(II)) and five different amino acids (L-Cysteine, LPhenylalanine, LGysine, LArginine and L-Aspartic acid) with hydrogen peroxide and guaiacol. According to the results, Cu(II), Mn(II) and Fe(III) increase the POD activity, Co(II), Zn(II) and Pb(II) have almost no effect the enzyme activities and Hg(II) and Sn(II) decrease the POD activity. The tested amino acids had inhibitory effect to dill Guaiacol POD activity. Keywords— Amino acids, metals, peroxidase, dill.